I have a Garmin Vivoactive (not HR) that's about 6 years old. (I know this forum is for Vivoactive 3 Series but I couldn't find a forum for the Vivoactive).
A few months ago, I noticed that it was turning itself off for no reason. I would long hold the power button for a few seconds, and after a few tries, it would turn itself back on. It would then stay on maybe for a few minutes before turning itself off again, and I'd repeat the process. Sometimes it would go "back to normal" and stay on "permanently" for several days or weeks. I seldom let the battery run down completely - I usually charge it to between 80 and 100% when the power gets down to below 20%. So it's not powering itself off due to the battery being depleted. Anyway - it's been fine for around 5-6 weeks, then last night it powered itself off and I battled to get it turned on again. Holding the power button had no effect. I must have tried 20-odd times. I put it on charge, and it stayed off. I kept trying and eventually it turned on and I went to sleep with it on. This morning I woke up and the watch was powered off. Again, I tried several times to turn it back on. Once or twice it displayed the "Garmin" briefly before turning off again. I put it on charge, and long-held the power button for over 30 seconds. Nothing. Tried to power it on a few times and eventually it did turn on (40-something % battery). I let it charge up to 70-odd % then put it on and it's stayed on for a few hours now.
So - any diagnosis?
